Implement IntoDiagArg for hir Namespace

Author: Xiretza

compiler/rustc_errors/src/diagnostic.rs

@@ -6,6 +6,7 @@ use crate::{
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_error_messages::fluent_value_from_str_list_sep_by_and;
 use rustc_error_messages::FluentValue;
+use rustc_hir::def::Namespace;
 use rustc_lint_defs::{Applicability, LintExpectationId};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::Symbol;
@@ -158,6 +159,12 @@ impl IntoDiagArg for DiagArgValue {
     }
 }
 
+impl IntoDiagArg for Namespace {
+    fn into_diag_arg(self) -> DiagArgValue {
+        DiagArgValue::Str(Cow::Borrowed(self.descr()))
+    }
+}
+
 impl Into<FluentValue<'static>> for DiagArgValue {
     fn into(self) -> FluentValue<'static> {
         match self {

compiler/rustc_lint/src/lints.rs

@@ -8,7 +8,7 @@ use rustc_errors::{
     codes::*, Applicability, Diag, DiagArgValue, DiagMessage, DiagStyledString, EmissionGuarantee,
     LintDiagnostic, SubdiagMessageOp, Subdiagnostic, SuggestionStyle,
 };
-use rustc_hir::def_id::DefId;
+use rustc_hir::{def::Namespace, def_id::DefId};
 use rustc_macros::{LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::{
     inhabitedness::InhabitedPredicate, Clause, PolyExistentialTraitRef, Ty, TyCtxt,